Well one had to say the whole premise of 'couldn't find evidence thus fact didn't exist' was fishy even before the article started digging out the evidence that reseaecher somehow missed.
Not really. The one thing he's correct about is that, if NINA was a real and widespread phenomenon, it would show up in certain pieces of documentation of the era -- newspaper want ads, for example (we actually have fairly large archives from the relevant era; it's not like something from thousands of years ago where it's plausible that no documentation would have survived.) His problem was that he didn't look deeply enough, and once he drew the initial wrong conclusion, he invented a totally wrong theory to explain it.
True. I think what he assumed was that it would show in other types of documents (like discrimination lawsuits, news showing revolt of the Irish against this policy, etc)
But I suspect this was very common and accepted, unfortunately.
I wonder if the big reason for these completely different results in the underlying counting experiment is that the later research was done after ocr had improved so much that the searches had very different samples of the papers.
My reading is the opposite. He started with a theory and then did a shallow search to bolster his pre-conceived theory, ignoring or discounting any findings that didn't fit.